A PCI-Based, Multiple-Payload Processing System for the DSX Flight Experiment

The need rapidly to accommodate a variety of diverse payloads, each with its own data processing and command/telemetry protocols, is increasingly common in the emerging responsive space environment. On the AFRL Demonstration and Science Experiments (DSX) spacecraft, the Experiment Computer System (ECS) provides communication interfaces, mass data storage, and complex processing for ten different payloads, each from a different organization, some of legacy design and some developmental, while providing a single, simple interface to the host spacecraft. In this paper we discuss the hardware and software design of the ECS with a view to clarifying how a single architecture has supported and isolated the complexity of a variety of different payloads. Of equal importance, we show how an aggressive program of early integration testing, using hardware and software prototypes representing the payloads at various stages of development, has reduced the risk of payload integration, and isolated the host spacecraft from the vicissitudes of payload development.